You'd be surprised! Among non-software management types, they often think of the code as extremely valuable IP and a trade secret. I'm a CTO and I've made comments before to non/less technical peers about how the code (generally speaking) isn't that big of a secret, and I routinely get shocked expressions. In one case the company almost passed on a big contract because it required disclosure of the source code (with an NDA). When I told them that was a silly reason and explained why, they got it, but the old way of thinking still permeates and is a hard habit to break.
Edit: Fixed errant copy pasta error. Glad that wasn't a password :-)